Adequate iodine intake of Slovenian adolescents is primarily attributed to excessive salt intake

Abstract

In Slovenia, table salt iodization has been applied to combat iodine deficiency. Recently, we found that Slovenian adolescents attained iodine sufficiency (median urinary iodine concentration was 140 microg/L; prevalence of goiter was <1%). National data indicate that salt intake of Slovenian population is too high (150% above the recommended limit); therefore, we hypothesized that sufficient iodine intake in adolescents can be primarily attributed to excessive salt intake. In a cross-sectional study, we investigated iodine and salt intake in Slovenian adolescents as well as the contributions of different foods to their intake. We determined the iodine and salt intake of a national representative sample of 2581 adolescents, aged 14 to 17 years, using the Food Frequency Questionnaire (FFQ). The FFQ covered habitual diets over the past year, and 2485 (96%) adolescents completed a valid FFQ (1370 girls, 1115 boys). The iodine intake was 189.7 +/- 2.6 microg/d (mean +/- standard error of mean), well above the recommended 150 microg/d (P < .001). Table salt was by far the biggest dietary source of iodine and sodium for both sexes. Total salt intake (mean +/- standard error of mean, 10.4 +/- 0.2 g/d) significantly exceeded the upper World Health Organization limit (<5 g/d, P < .001), especially in boys (11.5 +/- 0.3 vs 9.4 +/- 0.2 g/d in girls, P < .001). The main food sources of salt were table salt (33%), bread (24%), salty snack products (10%), meat products (8%), fish products (6%), and milk (4%). Salt intake from foods, excluding table salt, was 6.9 g/d (67% of total salt intake). We conclude that although Slovenian adolescents are iodine sufficient, their salt intake, especially among boys, is too high. Several nutritional interventions are proposed to reduce total salt intake while ensuring adequate iodine intake.